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Syntheses and properties of polyurethanes containing side‐chain azobenzene groups
Author(s) -
Kim MiRa,
Kim PhanSeok,
Kang EunHee,
Ha ChangSik,
Lee JinKook
Publication year - 2003
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.931
Subject(s) - azobenzene , polyurethane , photochromism , polymer , side chain , materials science , condensation polymer , polymer chemistry , composite material , nanotechnology
Polymers containing azobenzene groups have the characteristic reaction of photo‐induced cis–trans isomerism. The study of new materials for optical information storage has prompted making use of these photo‐isomerizations. In this study, we report the syntheses and properties of four different polyurethanes (DR‐PU n s) containing azobenzene groups in the side‐chains. The structurally similar polyurethanes (DR‐PU n s) were synthesized by the polycondensation reaction of Disperse Red 19 (DR 19) and four different diisocyanates in dimethylformamide. By introducing of DR 19 into the polymer, we obtained polymers containing a photochromic group in the side‐chain. The weight‐average molecular weights of the DR‐PU n s were in the range 5500–12 900. The T g s of the DR‐PU n s range from 119.5 °C to 157.0 °C, depending on the structure of the diisocyanate. Optical properties and solubilities of the polyurethanes were compared. The diffraction efficiencies of films were measured as a function of the reaction time. Typically, the diffraction efficiencies of the DR‐PU1 film prepared from toluene 2,4‐diisocyanate were observed up to a level of 0.25%. For the DR‐PU1 film, the effect of the intensity of the induced laser beam on the diffraction efficiency is also discussed. © 2003 Society of Chemical Industry